Patent Foramen Ovale » Thorax
Q21.1

Definition:

The foramen ovale is a small hole in the atrial septum that is used during fetal circulation to speed up the travel of blood through the heart, flowing from right to left, and it closes at birth, when pressure increases at left when breathing starts. If not closed, the anomaly is called patent foramen ovale, a form of inter-atrial shunt. This type of defect generally works like a flap valve, only opening during certain conditions when there is more pressure inside the chest as during strain defecation, cough, sneeze.

Notes:

Do not register the patent formen ovale as a congenital malformation, when it occurs in preterm infants or at an altitude above 2000 meters.